Whereas the Southern Australian and Queensland railways are called upon to meet the demands of agriculture, the roads of Western Australia, on the other hand, have been laid out to satisfy the extensive mining movements along the western shore of the island continent. The engineers, however, have not been called upon to face particularly stern grapples with Nature, owing to the country traversed being, for the most part, of a give-and-take character, and to there being an entire absence of high mountains and wide, rushing rivers. There is only one chain of hills of any magnitude that has to be crossed by the lines. This is the Darling range, which runs parallel with the coast from near Geraldton to the southern extremity of the country.
In order to gain the gold-fields around Coolgardie, as well as the eastern and southern stretches of the State, the difficulties confronting the engineer in connection with this low ridge were not so great as those prevailing in New South Wales. For instance, only one tunnel, 1,096 feet in length, has had to be bored. Indeed, the engineer seized the opportunity to build the line cheaply to such an extent that the lowest watermark in this respect, bearing in mind the configuration of the country, may be said to have been attained. True, the grades and curvature are heavy, the former running up to as high as 1 in 50 (2 per cent.), while the curves are of 266 feet radius. Some of the most difficult spurs in this range are traversed by the line which taps the extensive coal-fields in the Collie district—the bulk of the coal used in the State is obtained here—where sharp curves of 176 feet radius, and banks rising 1 in 40, have been introduced.
The first railway built in Western Australia was a short line from the coast to Northampton. This was completed in 1879. In those early days the finances of the country were at a very low ebb, and the engineer was forced to carry his track through the hilly country with the minimum of earthwork. The result was that curves so sharp as 88 feet radius were adopted.
The Upper Darling Range railway also deserves more than passing notice. It leaves Midland junction at the foot of the hills, and 10 miles from Perth. The precipitous character of the spurs so puzzled the engineer that he was driven to imitate the method of extrication from a difficulty of this description practised in New South Wales. He had to “zigzag” the line up the face of the bluff. Another feature of interest is on the spur from the eastern railway, known as the Smith’s Mill branch. A deep cut had to be driven through a hill, which the excavators, when they set to work, found to be a solid mass of pipe-clay!
Though the engineering trials on the railways in this State may not compare in calibre with those in other countries, there is one other difficulty which is far more significant from the railway’s point of view. I refer to the question of water supply. On the coast, where the rainfall varies between 15 and 40 inches per annum, this does not occasion any apprehension, but rain becomes scarcer and scarcer as the great interior deserts are approached. This condition prevails along a belt 150 miles or so wide, extending from Albany to Geraldton. When the discovery of gold at Coolgardie, some twenty years ago, sent a wave of excitement round the world, the miners and others who rushed to the El Dorado suffered terribly from the dearth of this indispensable commodity, and when the mines were set to work it hampered operations to a very pronounced degree. In the gold country the rainfall does not exceed six inches per annum, and consequently water had to be husbanded carefully.
The mining activity, however, brought about a remarkable expansion in the iron road, which pushed inland for nearly 600 miles. Then the water question became one of vital importance, because the locomotives required copious and frequent drinks to slake their tremendous thirsts. To bring this article up from the coast was costly. The scanty rainfall was collected so far as possible by impounding, but the water thus secured was found to be useless for the railway’s purposes. It became so heavily charged with deleterious substances, as it flowed over a salt-impregnated soil, that it set up heavy incrustation in the boilers.
This was a serious drawback, because it reduced the life of the engine’s internal organs very materially, and militated against the iron horse’s efficiency. To remedy this state of affairs, the earthen dams constructed at various points along the route, which formed small reservoirs, were supplemented by condensing plants. The most notable installation of this description was completed at Coolgardie. This plant was designed primarily to utilise the salt water from the adjacent mines. The Coolgardie condenser was capable of supplying about 60,000 gallons of fresh water per day, at a cost of 37s. 6d., or say $9 per 1000 gallons, and to furnish this requirement entailed an expenditure of £15,000, or $75,000, on the apparatus. A large distilling apparatus was set up also at Geraldton to supply the Northern railway running into the Murchison gold-fields, where the water question was also a serious factor.
THE ENTRANCE TO THE TUNNEL, 1,096 FEET LONG, THROUGH THE DARLING RANGE
This is the only tunnel on the West Australian Government Railways.